Reversing-valve for steam-engines.



PATENTED MAY 12, 1908.

J. GARDINER.

. REVERSING VALVE FOR STEAM ENGINES.

APPLICATION FI ED MAR. 4. 1907.

mwu/

m: rumpus pzrsns :0, WASHINGTON, o. c.

nrrnn s JOHN GARDINER, OF PORTLAND, OREGON.

REVERSING-VALVE FOR STEAM-ENGINES.

Specification of Letters Patent.

Patented May 12, 1908.

Application filed March 4, 1907. Serial No. 360,578.

To all whom it may concern:

Be it known that I, JOHN GARDINER, a citizen of the United States, and aresident of Portland, in the county of Multnomah and State of Oregon,have invented a new and useful Improvement in Reversing Valves forSteam-Engines, of which the following is a specification, referencebeing had to the acoompanying drawings as constituting a part thereof.

This invention relates to reversing valves of the type of sawmillengines which have become favorably known and are now extensively used,and it has for its object to improve the reversing valve so as to removecertain serious objectionable features thereof. In short, in thereversing valve of the engine referred to, the same was not wellbalanced, and as a result of such defect, its movement at times was verysudden, which sudden movement of the reversing-valve, being transmittedthrough its connections to the operating lever, was a constant menace tothe safety of the operator.

In order to more readily understand the nature of my improvements, Iwill in the first place explain the drawings; Figure 1, thereof,represents a partial plan section, of an engine comprising duplicatecylinders, slide-valves controlling the admission of the steam in thecylinder, and a central reversing-valve controlling the passage of steamto the res ective slide-valves; and Fig. 2 is a verticaflongitudinalsection, taken on a line a;w of Fig. 1.

The cylinder, 0., (the duplicate of which would appear on the left side,if the drawing were extended in that direction), has the usual ports,I), 1), connecting the valvechamber 0, controlled by a valve (1, and thechamber 0 is connected by ports, e, c, with the chamber f, of thereversing valve 9. The live steam is admitted through port it into thereversing valve-chamber f, and the exhaust steamis exhausted from theends thereof, through ports, t, t, connected by a passage 9', anddischarges through exhaust pipe is.

As heretofore constructed, the reversingvalve g was not made as shown inthe drawings, but comprised two solid pistons, con nected together, andconsequently the exhaust steam from the upper end of the reversing-valvechamber had no other outlet than the passage to the exhaust-pipe 76.Now, in steam engines of the type re ferred to, full steam pressure iscarried practically to the end of the stroke of each iston,

and, in consequence, the pressure of t e exhaust steam in thereversing-valve chamber is approximately that of live steam, at theinstant of exhaust. And therefore, when the steam was exhausted from theupper end of the reversing-valve chamber, the passage j offered suchfrictional resistance thereto as to cause an unequal pressure above andbe low the reversing-valve, producing the sudden movement of the lattercommonly known as a kick. To remedy this condition, I have made myreversing-valve g with a central passage-way g, connecting both ends. ofthe reversing-valve chamber, and which passage-way, leading direct tothe exhaust-pipe 7c, acts as an auxiliary to the passage j and causesthe pressure at both ends of said chamber to be equal at all times; andin consequence the shifting of the reversingvalve by the operator isreadily accomplished; the valve moving easily, being freed from anyinterfering pressure of steam.

I claim:

1. In a steam engine, the combination with a valve chamber formed withinlet and outlet ports, a slide valve in said chamber, a reversing valvechamber having ports communicating with the ports of the other mentioned valve chamber, said reversing valve chamber having two exhaustports, a hollow reversing valve in the reversing valve chamber betweenthe two exhaust ports, said valve being open at both ends andcommunicating with its chamber, the wall of the reversing chamber havinga passage to connect the two exhaust ports, said passage having anopening for the final exhaust of the steam at a point in alinement withthe hollow reversing valve.

2. In a steam engine, the combination with a pair of valve chambersformed with inlet and outlet ports, slide valves in said chambers, areversing valve chamber having orts communicating with the ports of theother mentioned valve chambers, said reversing valve chamber having twoexhaust ports, a hollow reversing valve in the reversing valve chamberbetween the two exhaust ports, said valve being open at both ends andcommunicating with its chamber, the wall of the reversing valve chamberhaving a passage to connect the two exha'ust valve being open at bothends and communicating with its chamber, the wall of the reversing valvechamber having a passage to 15 connect the two exhaust ports, saidpassage having an opening located at a point agreater distance from oneof the exhaust ports of the reversing valve chamber than from the otherof said ports for the final exhaust of the steam. 2

JOHN GARDINER. Witnesses:

T. J. GEISLER, OEoIL Lone.

